Carburetors



May 19, 1959 AG. E. RAYNOR CARBURETORS Filed Sept. 6, 1957 INVENTQR.6776er! E /Qaynor BY ATTOR/VY United States Patent CARBURETORSGilbert`E. Raynor, Tulsa, Okla. Application September 6, 1957, SerialNo. 682,428 7 Claims. (Cl. 261-50) Patent No. 2,841,374 dated July 1,1958 and entitled- Carburetors An internal combustion engine, or thelike, is normally utilized in combination with a carburetor providedwith a venturi throat for reducing the pressure of the incoming airstream in order to siphon fuel, such `as` gasoline, from a supplyreservoir into the air stream. The vaporized fuel is mixed with the airstream to provide for combustion thereof as required to supply the powerfor operation of the engine. Most of the carburetors in use today areprovided with a venturi throat of a xed size wherein the pressure dropor pressure differential created thereby is varied by the change of thequantity of air being drawn through the carburetor,

by the suction force of the engine. If the fixed venturi throat is smallenough to create suction pressures for fuel ow at low engine speeds, itwill usually restrict the ow of air and fuel at the higher engine speedswherein a Ihigh rate of ilow is required. In order to solve thisprob-lem, many fixed venturi carburetors have been developed havingmultiple barrels in order to more eiciently supply the air-fuel mixtureto the engine throughout the operating range thereof. These multiplebarreled carburetors are of a complex structure and are usually Veryexpensive in construction.

` The present invention contemplates a novel carburetor provided with avariable venturi section which automatically adjusts the throat area tothe quantity of air required by the engine, and maintains `asubstantially reduced venturi pressure which is proportional to theengine requirementsthroughout the operating range of the engine. Thus, amore accurate proportioning of the fuel with respect `to the air may beprovided for the engine operation. The variable venturi provides theSuction pressure required for fuel flowwith only a small drop in the`pressure maintained in the lower pressure section `of the carburetor.As a result, more pressure is available for moving the fuel-air mixtureinto the engine cylinders, thereby permitting more power to be producedfby. the engine. A `metering pin is provided for regulating the fueliiow, .and the venturi maintains a `vacuum even during idlingconditionsof the engine. Thus, no special idling systems are needed with the novelcarburetor. The variablcventuri section automatically maintains the mostdesirable `pressure drop and flow of air therethrough, fand the`metering pin functions to assure an optimum `fuel-air ratio for thevarious `engine operating conditions. 1 l

tially conical shaped outer housing 12. The housing12` with respect tothe quantity of air flowing through the venturi to provide the mostdesirable fuel-air ratio for the engine throughout the operating rangethereof.

Another object of this invention is to provide a novell carburetorhaving a venturi section of variable throat size for maintaining asubstantially reduced pressure drop of the air stream passingtherethrough which. is proportional to theengine requirements throughoutthe operatingrange of the engine.

A further object of this invention is to provide a car-` buretorw'herein the fuel is dispersed radially into the air stream passingthrough the venturi section for providing an optimum vaporization of thefuel.

A still further object of this invention is to provide a carburetorwherein a portion of air is mixed with the fuel prior to dispersal ofthe fuel into the primary air stream, thereby facilitating thevaporization of the fuel.

Still another object of this invention is to provide a novel carburetorhaving an automatically variable venturi throat which is simple andeicient in operation and economical and durable in construction.

`Other objects and advantages of the invention will be evident from thefollowing detailed description, read in conjunction with theaccompanying drawings, which illustrate my invention.

In the drawings:

Figure 1 is a sectional elevational view of a carburetorl embodying theinvention.

Figure 2 is a perspective view of a ing the invention and with a forpurposes of illustration.

carburetor embodyportion thereof cut away Referring to the drawings indetail, reference character` 10 refers in general to a carburetorcomprisinga substanis open to atmospheric pressure at one end 14thereof, as shown in Fig. 2. A suitable threaded connection member 16extends transversely into the housing 12 in the proximity of thelowerportion thereof for connection with a fuel supply line (not shown)from a fuel pump (not shown) or other fuel source, for a purpose as willbe hereinafter set forth. A reduced neck portion 18 is provided on thehousing 12 opposite the open end 14 thereof and is provided with asuitable throttle valve 20 secured therein in any well known manner. Anoutwardly extending circumferential flange member 22 is provided on theoutermost end of the neck portion 18, and isprovided with a plurality ofcircumferentially spaced apertures 24 for securing the carburetor 10 to1the induction system of an internal combustion engine, or the sleevemember 30 therein. The sleeve 30 like (not shown). l

A diametrically disposed cross bar member 26 extends across the open end14 of the housing 12, and is provided with a central aperture 28 forrigidly supporting a tubular is concentrlcally disposed within thehousing 12 and extends downwardly therein, as clearly shown in thedrawings. d The sleeve member 30 is provided with an outwardly extendicir` cumferential ange 32 at the inner or lower end thereof i d forreceiving one end of a suitable helical spring 34 which is disposedaround the sleeve 30 thereabove. A plurality of circumferentially spacedapertures 36 are provided in` the flange 32`for a purpose as will behereinafter set" forth. A cylindricalhousing 38 is slidably disposedaround the sleeve member 30 for encasing the spring 34.

The cylinder 38 is provided with an inwardly extending circumferentialange 40 at its upper end for receiving the uppermost end of the spring34 thereagainst, as clearly shown in the drawings. A plurality of spacedports 42 are provided in the cylinder 3 8 for admitting bleed air atatmospheric pressure into the interior of the cylinder 38X.

`A movable cone assembly 44 is suitably secured or integral with thelower end of the cylinder 38. The cone assembly 44 comprises an upperplate member 46 of a substantially annular conguration. Acircumferential tapered portion 48 is provided around the outerperiphery of the platel 46. The outer rim or tapered portion 48 isshaped to form an` inlet for a venturi throat section 50 between themovable cone assembly 44 and the inner peripheryof the` housing 12. Asleeve member 52 of aj' diameter' than the, cylinder 38 is4 Centrallyydisnosed 9.111 the. plat@ 46ml extends downwardly there.- from toprovide an air well portion. The upper end 54 of the sleeve 52 is openand is in communication with the` interior of the cylinder 38. Thus,ai-r at atmospheric pressure which enters the cylinderl 38 through theports 42 will be communicated to the air well 52. The apertures 36 inthe flange 32 permit the air to flow Adownwardlyifrom the cylinder 38into the air well S2 at all times'during the operation of the carburetor1d. A central aperture 56 is provided in the bottom of the well 52 toprovide a bleed air orifice. A tapered metering pin 58 is threadedlysecured within the spring hanger sleeve and extends downwardly throughthe bleed air orifice 56 for regulating the flow of air therethrough aswill be hereinafter set forth.

A vent plate 60 is rigidly secured to the under side of the -upper plate46 by means of suitable spaced vent bushings`62. The plate 60 is spacedfrom the plate 46 by means of circumferential shoulders or outwardlyextending anges 64 provided on each of the bushings 62. Thus, afueldispersal space 66 of a substantially annular configuration isprovided between the upper plate 46 andthe vent plate 60. A float bowl68 is carried by the vent plate 60 and extends downwardly therefrom toprovide a leakproof container for fuel. The vent bushings 62 extendthrough the plate 60 to freely admit air at atmospheric pressure intothe float bowl 68. A cylindrical housing 70 extends downwardly from thecentral portion of the vent plate 60 and is concentrically disposedaround the sleeve member 52 to provide a fuel emulsion well. I'hehousing` 70 is open at the top thereof for communication with the fueldispersion area 66. A centrally disposed fuel orice 72 of a smallerdiameter than theV orifice 56 is provided at the bottom of the housing70, through which the metering pin 58 extends into the fuel bowl 68K.The outer periphery of the fuel bowl 6 8 cooperates with the housing 12to provide an outlet 74 for the venturi throat 50.

A suitable connection member 76 is provided at the bottom of thefuelbowl 68 for receiving one end of a flexible conduit 78. The opposite endof the conduit 78 is suitably connected to the connection member 16. Inthis manner, communication is established between the fuel pump or otherfuel supply source (not shown) and the fuel bowl 68, It is to be notedthat the conduit member 78` is of a exible construction, and thereforedoes notl in any manner hinder the. reciprocal movement ofl thel coneassembly44. within the housing 12, as will be hereinafter set forth. Anannular iloat member, 80 is disposed within the fuel bowl 68 around, thehousing 70. A bell crank or lever arm 82 is suitably secured to thelowersurface of the float 80 for alternately opening and closing aneedle valve member 84 upon actuation of the tloat 80 to maintain arelatively constant fuel level in the float bowl 68 as is well known.The needle Valve 84 controlsthe ilow of fuel from the connection memberv76 into the fuel bowl 68, It will bel apparent from Fig.

l that a raised position of the oat will move the lever arm 82 forclosing the needle valve 84, thereby precluding the flow of fuel intothe fuel bowl 68. Conversely, a lowered position of the float 80 willmove the lever arm 82 to a position for opening the valve 84, therebypermitting `fuel to ow through the valve and into the fuel bowl 68.

The entire inner conc assembly 44, including the fuel bowl 68 and uppercylinder 38, is free to move reciprocally within the outer housing 12.The spring hanger tube 38 functions as a central guide for assuring aneiiicient reciprocal movement of the cone assembly 44: The pressure ofthe spring 34 bearing upwardly against the flange 40 of the cylinder 38sconstantly urges the entire cone assembly 44 toward an upward directionwhereby the outer periphery of the tapered section 48 will be in contactwith the inner periphery of the housing 12, for closing the venturithroat 50. The metering pin 58 may be threadedly adjusted within thesleeve 30 for placing the lower end 86 of the pin in substantially anydesired` longitudinal position within the fuel bowl 68 whereby thereciprocal movement of the inner cone assembly 44 will move the orifices56 and 72 to positions relative to the taper of the pin for metering theliow of fluid therethrough. The downward movement of the cone assembly44 will be limited by the flanges 4i) and 36 and the spring 34 disposedtherebetween. ln order to simplify the explanation of the operation ofthe carburetor 10, the chamber 88 within the housing 12 and above thecone assembly 44 will be designated the inlet chamber, and the chamber90 within the housing 12 below the cone assembly 44 will be designatedthe low pressure chamber.

Operation The operation set forth herein relates to the carburetor 10 asutilized with an internal combustion engine (not shown). lt will beapparent, however, that the carburetor is also applicable to utilizationin other fields.

The carburetor 10 is suitably secured adjacent the engine with the neckportion 18 in alignment with the intake pipe (not shown) of the engineas is well known in the industry. The tiow of iiuid through the neckportion 18 into the engine is controlled by the throttle valve 2i) inthe normal manner. When the engine is at rest, the pressure in the inletchamber 88 and low pressure chamber 9i) will be equal, and the spring 34will urge the inner cone assembly 44 toward its uppermost positionwithin the housing 12. ln this manner, the venturi throat 50 will beclosed and no air will be delivered therethrough to the engine. Inaddition, the largest crosssectional area of the tapered lpin 58 will bedisposed in the orifices 56 and 72 when the cone assembly 44 is in itsuppermost position. Thus, since there is no flow of air through theventuri S0, no suction pressure will be present to move fuel into thefuel dispersal space 66. However, both the orifices 56 and 72 aredisposed below the level of the fuel within the fuel bowl 68. Thus, thefuel will ow by force of gravity past the metering pin 58 to fill theemulsion well 52 to a depth equal to the level of the fuel within thebowl 68. It will be apparent that the metering pin 58 may be adjusted,or lowered or raised within the sleeve 30 by means of the threadedconnection therebetween, thus regulating the fuel ow and eliminating thenecessity of special idling systems for the, carburetor' 10.

When the engine is started, the action of the pistons (not shown)therein will reduce the pressure in the engine intakemanifold. Thus, thepressurein the low pressure chamber 90 will be reduced accordingly. Theperiphery of the fuel dispersal space 66 is open to this reducedpressure since the space 66 is disposed below the upper plate member 46.Therefore, the initial pressure drop resulting from the starting of theengine will reduce the pressure in the fuel dispersal space 66 and intheemulaseaaos sion well 70 which is in communication therewith. Theatmospheric pressure admitted through the vent bushings 62 into the fuelbowl 68 and acting on the surface ofthe fuel therein and atmosphericpressure admitted through ports 42 and apertures 36 to the bleed airwell 52 will force the fuel in the emulsion well 70 and bleed air well52 upwardly and out through the fuel dispersal space 66. In this manner,a -rich priming mixture of the fuel will be supplied to the engine forstarting thereof.

A continued piston action of the engine further reduces the pressure inthe low pressure chamber 90 until a stifli- `ciently great pressuredifferential is created between the low pressure chamber 90 and theinlet chamber 88 to overcome the tension of the spring 34. When thisoccurs, the movable cone assembly44 is moved downwardly within thehousing 12 and toward the enlarged portion of the housing. This opensthe venturi throat 50 whereby air will flow therethrough into thechamber 90. Simultaneously, the orifices 56 and 72 are moved `downwardlywith respect to the metering pin 58 whereby asmaller cross-section ofthe pin will be disposed in the orifices. Thus, air at atmosphericpressure will be permitted to ow downwardly from the bleed air well 52into the emulsion well 7 0` for mixing with the fuel admitted to theemulsion well70 through the fuel orifice 76 prior to dispersal thereoffrom the periphery of the dispersal space 66. It will be apparent thatthe lower the movement or the greater the distance travelled by the coneassembly 44, the greater the quantity of air" and fuel which will bedirected to the fuel dispersal space 66. This pre-mixing of a portion ofthe air with the fuel starts the vaporizing of the fuel prior todischarge into the dispersal space 66 and greatly facilitates the fullvaporizing and mixing of the fuel with the air for passing to theengine.

The velocity of the primary air moving through the venturi throat 50 isincreased as it passes through the venturi, inY accordance with knownlaws of physics. The increase in air velocity creates a decrease in theair pressure at the throat of the venturi 50. This lowered pressure iscommunicated to the emulsion well 70 through the dispersal space 66. Theatmospheric pressure acting on the surface of the fuel in the fuel bowl68 will thus force the fuel past the metering pin 58 in the fuel orifice72 and move the fuel upwardly therein. Simultaneously, the atmosphericpressure in the bleed air well `52 is forced downwardly around themetering pin 58 in the `ori1ice56 and into the emulsion well 70 whereinthe air mixes with the fuel in the well 70 to provide a fuelairemulsion. This fuel-air emulsion is discharged through the fueldispersal `space 66 for mixing with the primary air entering thecarburetor through the venturi throat 50. It will be apparent thatthe-pressure differential between the inlet chamber 88 and low pressurechamber 90 will be determined by the engine `requirelments. Thus, thereciprocal movement of the inner cone assembly 44 will be in accordancewith the operating requirements of the engine for automaticallysupplying the optimum quantity and ratio of air-fuel mixture to theengine.

The bleed air in the air well 52 facilitates the passage of the fuelthrough the emulsion well 70 and into the dispersal space 66 by reducingthe tendency of the fuel to adhere to the inner surfaces thereof.Furthermore, the pre-mixing of the air with the fuel permits the fuel tostart vaporizing during its movement toward the venturi 50. In addition,the bleed air assures an even distribution of the fuel through the fueldispersal space 66. thereby providing a more even mixing of the fuelwith the primary air at the venturi throat 50. The addition of morebleed air in proportion to the increase of fuel at higher rates of thefuel ow is necessary to maintain the advantages of the bleed air at thehigher ow rate ranges. As hereinbefore set forth, the bleed air flow isautomatically increased as the inner cone assembly moves downwardlywithin the outer housing 12, thereby assuring an efficient operation ofthe carburetor 10 throughout the operating range of the engine utilizingthe carburetor.

As the fuel-air mixture requirements of the engine are lessened, such asby a slowing down of the engine speed, or a back up of the manifoldpressure resulting during the process of rapid engine acceleration, thepressure differential between the inlet chamber 88 and low pressurechamber 90 is decreased. Thus, the spring 34 will function to urge theinner cone assembly 44 upwardly toward the small portion of the housing12 and toward a closed position. This reduces the area of the venturithroat 50 to reduce the quantity of air flowing therethrough, and movesthe orifices 56 and 72 toward the larger section of the metering pin 58to reduce the quantity of fuel and bleed air admitted to the fuelemulsion well 70 and the fuel dispersal space 66. When the inner cone isreturning to a reduced flow condition, the venturi vacuum will not bedestroyed, however, and the fuel flow will thus continue to beproportional. That is, there will be no momentary conditions of leanfuel mixtures which normally result from a collapse of venturi vacuumand interrupts the fuel liow to the engine, such as would occur if thesize of the venturi were fixed instead of variable. Thus, there is noneed for an acceleration pump, or the like, as an auxiliary agent forthe carburetor.

From the foregoing, it will be apparent that the present inventionprovides a novel carburetor having a variable venturi throat section forincreasing the clciency of an internal combustion engine, or the like.During periods of engine acceleration, the venturi area and fuel orificearea is automatically adjusted to admit the fuel-air mixture requiredfor engine operation regardless of the varying ow rate and the varyingpressures developed in the eugines induction system during acceleration.Thenovel carburetor maintains the venturi suction and assures anuinterrupted `fuel flow proportionate to the primary air passing throughthe venturi throat, whereby supplementary fuel need not be provided forthe engine, thereby resulting in a greater fuel economy. Conversely,when the engine decelerates, the venturi area and the area through thebleed air orice 56 and the fuel orifice 72 is reduced to regulate air owand fuel flow in accordance with engine requirements while maintainingoptimum fuel-air ratio. The carburetor is simple and efficient inoperation and economical and durable in construction.

Changes may be made in the combination and arrangement of parts asheretofore set forth in the specification and shown n the drawings, itbeing understood that any modilication in the precise embodiment of theinvention may be made within the scope of the following claims withoutdeparting from the spirit of the invention.

I claim:

l. A carburetor comprising a substantially conical shaped outer housing,a movable inner housing member concentrically `disposed within the outerhousing, a fuel reservoir provided within said inner housing, springmeans provided in the inner housing for constantly urging the innerhousing in one direction, an inlet chamber provided on one side of theinner housing and open to atmospheric pressure, a low pressure chamberprovided on the opposide side of the inner housing from the rstmentioned side, said inlety chamber and low pressure chamber providingpressure differentials across the inner housing for overcoming thespring pressure for moving the inner housing in a direction opposed tothe spring pressure, means provided in the inner housing for dispersingthe fuel from the fuel reservoir and into the outer housing, meteringmeans for regulating the flow of the fuel from the reservoir, and meansfor controlling the flow of fuel into the fuel reservoir.

2. A carburetor comprising a substantially conical shaped outer housing,an inner housing reciprocally disposed within the outer housing, saidinner housing cooperating with said outer housing to provide a variableaseroo venturi throat therebetween, an inlet chamber provided onoin'eside of the inner housingya lovvp'ressur'e chamber provided on theopposite yside of the inner housing, spring means provided in the innerlhousing for urging the inner housing in a direction tovvardfiliesmaller portion of the outer housing to close ventri throat, said inletchamber and 10W pressure 'chamber providinga p're'ssuredifferentialacross the inner housing for overcoming the spring pressure to open theventuri throat, afuel reservoir Iprovided witliih 'the inner housing,means fo'r 'direeting the fuel from the reservoir intothe venturithroat, means for mixing air Iwith the fuel before dispersal thereof,said fuel reservoir Lopen tio/atmospheric pressure for moving the fuelyout `ofthe reservoir, adjustable "metering means for regulating ytheflovvoffuel from the reservoir, and means for `eontrolling `the florvoffuel Yto the reservoir.

n 3. carburetor comprising a substantiallyy conical shaped outerhousing, 'an inner housing 'reciprocally disposed Within the outerhousing, 'said innerhousing icooperating with said outer housing toprovidea variable venturi throat, an inlet chamber provided ou one sideof the inner housing and open to atmospheric pressure, a 10W pressurechamber provided on the opposite side of the Y inner housing forcreating a pressure differential thereacross, said inner housingresponsive to said pressure diiferential formoving the Venturi throattovariable posi- Itions ofopen, Va fuel reservoir 'provided Within theinner housing, 'means for moving the fuel from 4the reservoir to theAventuri throat inproportion to the air stream moving therethrough,adjustable metering means vfor regulating the fuelflo'w fromv'thereservoir, andmeans'fo'r -controlling the supply of fuel to the fuelreservoir.

4. A carburetor comprising a ysubstantially conical shaped outerhousing, 'an inner housnigreciprocallyl disposed Within the outerhousing, 'an Vinlet chamber Vprovided on one side of the innerhousing'and open yto atmospheric pressure, a low pressurechamber'provided on the opposite side ofthe inner housing `for creating'pressure differentials thereacross, said pressure differentialsproviding for reciprocal movement of the inner housing Within'the outerhousing to provide a variable venturi therebetweem'a fuelreservoirprovided withinthe inner housing, fmean's for dispersing thefuel radially'from the inner housing to the venturi throat,metering'means for tproportioning `the `fuel flow inrelation to the airstream moving through the venturi, said metering means adjustable forregulating the fuel flow from the reservoir, and fmfeans for controllingthe llo'w of fuel into the fuel resrroi 5. A carburetor comprising asubstantially conical 'shaped outer housing, an inner housingreciprocally disposed within `the outer housing, an inlet chamberprovided on one side of the inner housing and open to atmosphericpressure, a low pressure chamber provided on the opposite sidey of theinner housing for creating pressure Vdifferentials thereacross, saidinner housing cooperating CET 8 Wirth said 'outer housing to provide avariable venturi throat therebetween, vspring 1iheans provided intheinner housing for urging the inner `housing toward 'the smallest portionofthe outer "housing t'oclose the venturi throat, said pressurediierential "provided for overcoming the spring pressure in order tomove theinner housing in an opposite direction for 'opening of theventuri throat, a

"fuel reservoir provided Within the inner housing, a fuel dispersalchannel Vprovided in the inner housing and in communication With theventuri throat, means for moving the fuel from the reservoir into thefuel dispersal space in proportiony to "the ilow of air through theventuri throat, adjustable metering means for regulating 'the liow offuel from the reservoir, and means `'for regulating the fuel prior todischarge into the venturi throat for facilitating vaporization of thefuel, 'adjustable 'metering means for regulating the liow of fuel fromthe reservoir, and means to regulate the'ii'ow of fuel "into the fuelreservoir.

7. A carburetor comprising a substantially conical shaped outer housing,aninner housing eei'p'r'cally disposed `Within the Aouter housing 'toprovide v'a 'variable 'venturi throat therebetween, 'an upper chamberprovided in the outerhousing forcommunicating'atirosplrericl pressure tooneside yof the inner iho'u'sing, a lov'v'er chamber provided in theouter housing for creating a pressure'differental aeross the innerhousing, "spring ineamprovided in the inner housing for urging the innerhousingtoward the smallest portionof the outer housing for 'closing theventuri throat, said pressure diifere'ntial yprovided Yforovercoming'the spring pressurey to openthe venturiy throat, a fuelreservoir provided within the inner housing, means provided inthe innerhousingfor dischargingithe fuel into the venturi throat, means forregulating the discharge of fuel into the vventuri throat in proportionto the flow 'of air therethrough, adjustable metering means forregulating the llow of fuel from the reservoir, rneansffor mixing aportion'of'air with the fuel prior to'disehage thereof into the venturithroat, and meansfor "controllingthe `iiow of fuel into the fuelrservoir.

smc-Aug. 26, 1919 sept. 11, 1934

